There has been a growing trend in the engine industry to consider fueling engines with two fuels from a single fuel injector associated with each engine cylinder. The two fuels may differ from one another in at least one of chemical identity, matter phase and pressure. For instance, there has been increasing interest in powering compression ignition engines primarily with natural gas injected at a first pressure that is ignited from a compression ignited small pilot injection of liquid diesel fuel. However, in order to be viable, the fuel injector must generally have the ability to independently control both timing and quantity of the injection of the two different fuels. This in turn may require two separate electronically controlled valves housed within the single fuel injector. Finding a way to organize the plumbing, and arrange two independent electrical actuators and their associated control valves within a single fuel injector has proven to be difficult and problematic. Further complicating these problems are developing a control strategy that can satisfy the increasingly stringent performance demands required by modern fuel systems.
The present disclosure is directed to one or more of the problems set forth above.